Send to

Choose Destination
See comment in PubMed Commons below
Respir Physiol. 1994 Jun;97(1):13-24.

Contribution of the parasternal intercostals to inspiratory rib elevation in dogs.

Author information

Respiratory Muscle Research Unit, Katholieke Universiteit, Leuven.


To estimate the contribution of the parasternal intercostals to rib elevation during quiet breathing, parasternal intramuscular pressure, Pim, in the fourth interspace and displacement of the rib just below were measured in eight supine anesthetized dogs during: (1) bilateral stimulation of the parasternals, (2) quiet breathing before, after phrenicotomy, and subsequent vagotomy. During quiet breathing, the parasternal contribution averaged 66 +/- 12% of the rib elevation caused by inspiratory rib cage muscles. This contribution decreased in relative terms after phrenicotomy (37 +/- 14%) and subsequent vagotomy (26 +/- 14%) while it tended to increase in absolute terms (from 1.9 +/- 2.4 to 2.1 +/- 2.5 NS, and 2.4 +/- 2.4 mm P < 0.01, respectively). Rib elevation caused by inspiratory rib cage muscles increased after phrenicotomy (116 +/- 63%, P < 0.001) and subsequent vagotomy (279 +/- 60%, P < 0.001) as did Pim (19 +/- 10% NS and 41 +/- 36% P < 0.01, respectively). Moreover, the mechanical interaction of the parasternals among different interspaces measured in three other dogs, was likely to be limited during quiet breathing. We conclude that after diaphragm paralysis, the parasternals played a progressively smaller role while other rib cage muscles were increasingly recruited.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center